Sadhana's Research



Express protein
Set up crystal trays (use 24 well plates, start with condition listed in the PDB article and vary a little bit up and down in concentration)
ICM Virtual Screening (maybe Vina screen too? - get Christina's help)
Inhibition Assays
Determine IC50 of compound
Then compare best ICM ligand to best GOLD ligand in the wetlab




Week 14:
  • Since there were three proteins I collected from the FPLC, I did an enzyme assay for each one of them, however there was no enzyme activity. The OD reading was 0 for the most part
  • I also did an enzyme assay for Dr.B's PSTP sample prior to FPLC. Again, my enzyme was inactive.
  • I did an enzyme assay of all three increasing the concentration of enzyme I added to 10ng/ul. Since the solution didn't turn yellow, my enzyme was inactive.
  • Finally, I did an enzyme assay for my PSTP sample that was snap frozen, which didn't work as well.
  • Snapfrozen_sample-1.jpg
    Figure 1: Concentration of PSTP that was snap frozen in -80 degrees Celsius
  • Dr.B's_PSTP_before_FPLC-1.jpg
    Figure 2: Concentration of Dr. B's PSTP before FPLC
  • protein1-glycerol-1.jpg
    Figure 3: Concentration of protein 1 in 20% glycerol
  • protein3-glycerol-1.jpg
    Concentration of protein 3 in 20% Glycerol - Possibly PSTP?

Week 13:
  • Protein Expression
  • skipped characterization
  • FPLC
  • concentrated protein to 0.5ml and stored in 20% glycerol
  • elution1.PNG
    Figure 1: Concentration of Elution 1 sample after purification
  • Elution_2.PNG
    Figure 2: Concentration of Elution 2 Sample after Purification
  • FPLC.PNG
    Figure 3: FPLC graph


Week 12:
  • Enzyme Assay (2 Trials)
  • 1st trial - PTP1b as a control; used 60ul and 120ul of enzyme to test activity
    • PTP1b enzyme served as the positive control - turned yellow upon addition of pNPP substrate so enzyme works
    • PSTP did not turn yellow and the absorbance readings were 0.
  • 2nd trial - supplemented enzyme with manganese ions (final concentration is 1mM)
    • Tube A with 60ul of enzyme: 0.148 (absorbance)
    • Tube B with 120ul of enzyme: 0.107 (absorbance)
  • Need to do protein expression again...

Week 11: S - since the activity is below the control, the enzyme may not be active. I think the big bar in the second graph is an outlier. - May need to think about regrowing enzyme. Dr. B. (also may be worth comparing to PTP1b in same assay)
  • ACS
  • symBIOsis
  • Virtual Screening
  • Enzyme Inhibition Assay with and without TCEP
SB1.PNG
Figure 1: Enzyme inhibition assay test without TCEP

SB2.PNG
Figure 2: Enzyme Inhibition Assay with TCEP


Week 10:
  • Virtual Screening-working on primary and secondary runs for MW-set_3D.sdf Chembridge Library
  • SB_excel.PNG
    Figure 1: Best ranking list from first run of cb_306.


Week 9:
  • Enzyme Test
  • SB_pstp.png
    Figure 1: Absorbance of protein measured at 410nm
  • SB_excelPSTP.JPG
    Figure 2: Enzyme Activity - Absorbance at 410 nm vs Concentration of protein (nM).
  • Concentrated protein after FPLC (below are the concentrations after FPLC)
  • afterFPLC-beforeconcentration-102411.jpg
    Figure 2: Concentration of PSTP after it was diluted in buffer during FPLC - the concentration after Beer's Law calculation was 3.2uM.
  • afterFPLC-beforeconcentration-proteininquestion102411.jpg
    Figure 3: Concentration of unknown protein detected by FPLC
  • afterFPLC-afterconcentration2-102411-1.jpg
    Figure 4: Concentration of PSTP after concentrating it to 16uM (After FPLC) - the concentration after Beer's Law calculation was 10.5 uM
  • stored half of sample (.5ml) in 20% glycerol and snap froze the other half using liquid nitrogen
  • Crystallography workshop


Week 8:
  • Virtual Screened HF9, cd_306, MW-set libraries.
  • concentrated protein - combined elution 1 and 2 samples
  • concentratedElutionSB.jpg
    Figure 1: After concentrating protein-before washing the "walls" of the filter.
  • concentratedElution2SB.jpg
    Figure 2: After concentrating protein - after washing the "walls" of the filter.
  • FPLC
  • Sadhana - embed this image instead of putting it as a link..... Dr. B

Week 7: - Need images or Data - Dr. B
  • Virtual screening on PSTP - screened the HF9 library
  • worked on pymol image of PSTP
  • Dried characterization gel
  • lab report


Week 6: (YEAH, Sadhana..... - good expression - Dr. B)
  • protein purification - combined soluble fraction of tube A and tube B
  • protein characterization (ran gel)
    • lane 1: protein ladder
    • lane 2: sample 1 (post induction) flask A
    • lane 3: sample 1 (post induction) flask B
    • lane 4: sample 2 (soluble fraction) tube A
    • lane 5: sample 2 (soluble fraction) tube B
    • lane 6: sample 3 (flow through)
    • lane 7: sample 4 (wash)
    • lane 8: sample 5 (Elution 1)
    • lane 9: sample 6 (Elution 2)

SAM_0536.JPG
Figure 1: Page gel (protein characterization); Sample 1 in lanes 1 and 2 look like they are the elution samples..sample 1 is supposed look like samples 2, 3, and 4 because it should technically have many other proteins.

Concentrations of Elution Samples:

proteinpurificationelution1[1].jpg
Figure 2: Concentration of elution 1 sample (280nm)


proteinpurificationelution2[1].jpg
Figure 3: Concentration of Elution 2 sample (280nm)



Week 5: - Sadhana - show some data - what were the pellet weights??
  • Made page gel
  • protein expression continued: lysis step 4

Week 4: (Sadhana - show a screen shot of your BLAST image instead of posting a link to a WORD doc. - Thanks,DrB.)

  • DNA sequencing results: Samples 2 and 6 matched completely. Sample 5 had a 99% match in both the forward and reverse sequence. I will be using Sample 6 for protein expression because it had the highest concentration. (37.8ng/ul)
  • Transformation (Bl21 competent cells) - How many colonies? - Dr. B (46 colonies on plate A and 221 colonies on plate B)
  • Protein Expression - What was the pellet weight? - Dr. B (3.08g and 2.96g)
  • SAM_0528.JPG
    Figure 1: The top 2 plates are test plates with competent cells that had been left outside. The bottom two plates are my transformation plates with BL21 competent cells and my protein, PSTP. Plate A in the bottome ledt has 46 colonies and plate B on the bottom right has 221 colonies.
  • SAM_0532.JPG
    Figure 2: My transformation plates and overnight culture.

Week 3:
  • Centrifuged samples and retrieved the pellet (stored in -20 degrees Celsius)
  • Miniprep
  • Sent 3 samples (2,5,6) to DNA sequencing- The other samples had very low concentrations because I eluted with 100 ul of water as opposed to 50 ul of water.
  • Pymol Refresher
  • Virtual Screening Refresher (Completed Run 1)


Sadhana - looks good. - Dr. B

Week 2:
  • Preparation of pNIC-Bsa4 as Accepting Vector
  • Gel checked pNIC (not cut), so borrowed Adam's.
  • Cohesive End Generation and Transformation
  • Grew up culture and made master plate
  • sb_pnic.JPG
    Figure 1: Lane 1-skip, Lane 2-uncut pNIC, Lane 3-cut pNIC...Bsa1 did not cut pNIC....possibly due to an error in PCR cleanup

Week 1:
  • Ran secondary PCR on gel
  • Ran PCR Squared
  • PCR Cleanup on PCR Squared Sample
  • SB_PCR2.jpg
    Figure 1: Concentration of secondary PCR prior to PCR cleanup
  • sadhana_2nd_pcr.JPG
    Figure 2: Secondary PCR prior to PCR cleanup; Lane 1: 100bp DNA ladder; Lane 2: Secondary PCR
  • SB_PCRsquared1.jpg
    Figure 3: Concentration of PCR squared sample after PCR clean-up.

SAM_0389.JPG
Figure 1: 1ng of Plasmid pGFP was incorporated into the DH5 bacteria. A total of 240 colonies were grown

SAM_0387.JPG
Figure 2: 5ng of Plasmid pGFP was incorporated into the DH5 bacteria. A total of 424 colonies were grown.

SAM_0386.JPG
Figure 3: 25ng of Plasmid pGFP was incorporated into the DH5 bacteria. A total of 784 colonies were grown


sadhanab_1.jpg
Figure 4: Restriction Enzyme Digest Gel; Lane 2 is the DNA ladder, Lane 3 is the uncut plasmid, Lane 4 is EcoR1, Lane 5 is PvuII, and Lane 6 is EcoR1 + PvuII.

sadhanab_2.jpg
Figure 5: pmCherry gel; no bands present....possibly due to an error in the PCR or pipetting.

sadhana_pgbr22_gel.jpg
Figure 6: pGBR22 gel; Lane 1: skip, Lane 2: DNA ladder, Lane 3,4,5,6 Samples.

SAM_0433.JPG
SAM_0446.JPG